marsh



(No Model.) 2 She'ets--Sheet 1.

E. MARSH.

APPARATUS FOR FIRING STEAM BOILERS.

No. 438,080. Patented Oct. '7, 1890.

m; ncmms wanna co., PHDYO-LIYHO., vusummou, n4 0.

(No Model.) 2 Sheets-Sheet 2. E. MARSH.

APPARATUS FOR FIRING STEAM BOILERS.

No. 438,080. Patented Oct. 7, 1890.

Half

NITED STATES ATENT Enron.

EDWIN MARSH, OF LEEDS, ASSIGNOR OF ONE-HALF TO HENRY LEGGOTT, OF

BRADFORD,

APPARATUS FOR FIRI ENGLAND.

NG STEAM-BOILERS.

SPECIFICATION forming part of Letters Patent No. 438,080, dated October'7, 1890. Application filed March 25, 1890. Serial No. 345,231. (Nomodel.) Patented in England November 13,1888. No. 16,409-

To all whom it may concern:

Be it known that I, EDWIN MARSH, a subject of the Queen of Great Britainand Ireland, and residing at Leeds, in the county of York, England, haveinvented certain Improvements in Apparatus for Firing Steam- Boilers andthe Like, (for which I have obtained Letters Patent in England,No.16,409, dated November 13, 1888,) of which the following is aspecification.

This invention relates to certain improvements in apparatus for firingsteam-boilers and the like, whereby a slow or fast rate of combustion,at the will of the attendant, may be obtained in the fire, coaleconomized, and more perfect combustion and greater freedom from smokeobtained. By my arrangement I am enabled to effect the removal of ashesand waste products of combustion by mechanical means, thereby effectinga saving of labor on the part of the attendants and with certain otheradvantages in regard to the main object of this inventiontheeconomization of fuel and the prevention of smoke from the furnace. Thefurnaces of boilers for the raising of steam have been hitherto suppliedwith what are generally known as dead-plates, furnace-bars, and bridgebehind-the bars. Upon the latter the fire is placed,- in the case ofinternal-fined boilers of the Lancashire and Cornish type, within theflue, and in other classes of boilers in a chamber built of fire-brickunderneath the boiler. The air for combustion is supplied, for the mostpart, to the under side of the furnace-bars and caused to pass throughthe spaces between the bars to the fire. Air is also admitted by variousmeans automatically or by hand through the door along the top of thefire. In all these arrangements when it is de sirable to remove theclinker ashes from the fire some portions of the furnace-bars areuncovered, when a large quantity of cold air rushes in. It is well knownthat at such times the efficiency of the boiler is for the time verymuch diminished; but by my arran gement no such drawback occurs when theclinker ashes are removed. The fire is during that operation effective,as no air can enter the flue except by first passing through the fire.My arrangement of furnace is also applicable to domestic ranges andstoves, as shown by Fig. 6, which represents a section through adomestic range or stove fitted with my improvement.

In the accompanying drawings, Figure 1 represents the front view part insection of a two-fined Lancashire boiler fitted with my apparatus. Fig.2 is a plan of the same part in section. Fig. 3 is a section throughline a b, and Fig. 4 a detail showing the connections between thelouverbars and catch for keeping same in the required position.

In accomplishing my object the dead-plate and fire-bars now in ordinaryuse are dispensed with, and in front of each furnace-tube A, I constructa chamber-B, wider at the bottom than the top, of silica or otherfire-bricks capable of standing a very high temperature, such as areused for blast-furnaces. front of each chamber is fitted with louverbars0, working on trunnions or short proj ecting shafts supported by sideplatesD, and which are capable of adjustment as to amount of opening bymechanical arrangement hereinafter described.

WVhen the louver-bars O are closed, the air is excluded from the fire inthe chamber B, and therefore the combustion is retarded, and when openedto varying degrees of inclination the combustion is more rapid-perhapsmost rapid and efiicacious when at an angle of about forty-five degrees.

Each louver-bar Cis prepared with an arm or lever E, which are connectedby bars F, mounted on the respective stud-pins G of the levers. One ofthe pins is extended, on which is mounted a pawl H, which engages with aratchet J for keeping the louver-bars O in the desired position. A linkK connects the lever L with the louver-bars C, and when the said leveris operated on its bearing-stud in an upward or downward direction thelouverbars 0 are opened or closed accordingly and retained in thedesired position by the pawl 5 H engaging with one of the teeth of theratchet J.

The bottom of the chamber Bis fitted with a sliding plate M, which mayhave a plain fiat surface, or may be of grid form, some- 10) The 70 whatas shown by detail, Fig. 5,in which case it is made to slide on a fixedplate having corresponding openings, so that when the openings areopposite the ashes are allowed to drop below, and when moved by thelever and connections Z, so that the solid part of the plateis oppositethe openings of the other, it is closed and all air excluded. In thecase when a plain plate M is fitted to the apparatus, as shown indrawings, when it is desirable to let out the ashes the louver-bars Oare raised in the manner as before described toward their horizontalposition, thereby lifting the bulk of the fire in chamber B from thebottom, so that when the sliding plate M is operated by the lever andconnections Z the ashes drop down into a hopper N, below which is atraveling endless non-combustible belt 0 of any length, revolving overpulleys P, which conveys the ashes from the hoppers N away from theboiler or boilers to any desired-position, depositing them down anincline, as at Q. The back portion of the chamber B is heated toredness, and by the air and smoke passing through the fire and inclinedopenings B it is consumed, thereby adding to the efficiency of theboiler, no cold air being allowed to enter the furnace-tubes A exceptthat which passes through the body of the fire in chamber B.

The fuel may be supplied to the fires by any of the well-knownmechanical stokers.

In the drawings the fuel is fed from the hoppers S by the revolvingcrushing-rollers T, operated by the driving-pulley U, coned for theregulation of speed through the train of gearing V. The shafts of thetwo crushing-rollers in each hopper are connected by spur-wheels IV W,so that both revolve in the direction of the curved arrows, thuscrushingand depositing the coal onto the fire below in the respectivechambers B. It is, however, well known that the principal object of allmechanical stokers hitherto in use is to project fuel evenly over thefire, involving various mechanical contrivances for accomplishing thatobject. The drawback to the more general adoption of such mechanicalstokers is the great wear and tear of the mechanical parts which effectthe projection of the fuel to varying distances onto the fire. In myimproved means of stoking all such parts are dispensed with and the fuelfalls vertically onto the fire in quantities capable of regulation bywell-known mechanical means.

In Fig. 6 the louver-bars O are mounted, as before described, andcapable of regulation as to amount of opening by the operatinglever L.The fuel in this case may be supplied through an opening at Y, which maybe provided with a door.

All the air required for combustion is drawn from the outside andinclined downward onto the fire through the openings between louverbars0 and through the openings R, formed in the brick-work in the fire-back,into the main flue provided with an ordinary damper D.

The bottom of the fire-chamber B is provided with a sliding plate M,which on being withdrawn allows the ashes to fall into the chamber 0,constructed similar to that of an ordinary range or stove.

\Vhat I claim is- 1. The combination of hopper S, from which the fuelfalls vertically into a chamber B, having adjustable louver-bars G, asliding plate M, ash-hopper N, and a carriage-belt 0, all arranged andoperated substantially as described.

2. In a mechanical stoker, the combination of the louver-bars O andoperating mechanism with the chamber having a perforated and inclinedback, and a sliding plate M at the bottom, all arranged and operatedsubstantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

EDWIN MARSH.

Witnesses:

JOHN WAUGH, JOHN GILL.

